The present invention relates to a radial piston machine and, in particular, a radial piston pump comprising a sealed rotor-stator unit received in a housing in an axially located, radially elastic and torsionally secured fashion, the rotor thereof being rotatable with a connected shaft situated in a coaxial extension of the rotor through a spring clutch engaging one rotor end face.
In hydraulic machinery, especially in pumps, noise produced by vibrations of single members is a frequent occurrence. The pressure pulsation in the pressure port is an important factor in the production of such vibrations.
In order to avoid such vibrations, with the aim to reduce the noise occurring in operation, a radial piston machine of the type referred to hereinabove is known from German Patent DE-AS No. 2,334,138. The rotor-stator unit possesses a central control pintle with radial grooves in which O-rings are disposed under prestress to thus hold the control pintle in the housing elastically. The control pintle and mounting hole are so dimensioned that no metallic contact occurs, the O-rings are the only connecting elements between the control pintle and the mounting hole. Because the pressure port of the machine is arranged between the O-rings, the O-rings assume not only a retaining, but also a sealing function with the pump in operation.
A disadvantage in this known arrangement is that with increasing compressive load on the O-rings, the elasticity is impaired, resulting in increased noise.